The total isolation valves, especially in three-way diverter configuration, combine the characteristics of strength and reliability with constructive solutions that make them particularly suitable for controlling aggressive and/or incontaminable fluids. The fluid comes into contact with the valve body and the sealing device only, wherein the sealing device typically consists of a membrane or a separating lever. This solution preserves the fluid from contamination, which can alter the chemical-physical characteristics thereof, and from excessive thermal shocks. The total isolation valves are thus suitable for applications in the food, biotechnology, chemical-pharmaceutical and physiological-medical sectors.
A known embodiment of a total isolation valve, in particular of the three-way type, is shown in FIG. 1. The valve, wholly indicated with reference numeral 100, is provided with a valve body 102 inside which a fluid is made to flow. Inside the valve body 102 there is a lever shutter 104 actuated by a magnetic drive solenoid 106. The movement of the lever shutter 104 is driven through a series of levers 108 and transmissions 110 that make the construction of the valve 100 complicated.
In addition, the total isolation valves provided with isolation lever require a particular configuration of the inlet and outlet conduits of the valve, consequently limiting the design freedom of the fluidic part of the valve itself. Indeed, in the three-way configuration the most common constructive choice, if not the only one, is to provide an isolation lever or a double membrane.
The constraints linked to the actuation also have an impact on the internal constructive geometries of the valve, complicating the design thereof at the expense of cleanliness and hygiene of the valve itself. This drawback is even more critical if one considers the typical applications in the biomedical or “food and beverage” technical fields.
Another example of a total isolation valve according to the prior art is described in document EP 0 085 298 A1. Also in this configuration of the valve, however, it should be highlighted how the constructive complexity both of the fluidic part, and of the actuation part is high in order to ensure the total isolation function. In the valve illustrated in document EP 0 085 298 A1 the conduits and the sealing areas, which through the opening and closing of pistons establish the direction of the flow, have critical areas in terms of hygiene. The conduits themselves have sudden changes of direction (angles at 90° and 180°) which do not promote normal flow of the fluid and thus increase the load losses of the valve.
Further examples of valves or devices for controlling the direction of the flow of a fluid are described, for example, in documents U.S. Pat. No. 4,278,110 A, GB 1 214 081 A, JP 2005-121209 A, WO 82/02076 A1, EP 0 126 608 A1 and US 2012/255739 A1.
The general purpose of the present invention is therefore to make a total isolation valve, in particular a total isolation diverter valve of the three-way type, which is capable of solving the aforementioned drawbacks of the prior art in an extremely simple, cost-effective and particularly functional manner.